JPS61227010A - Molding of resin material and device thereof - Google Patents

Abstract

PURPOSE:To enable to place resin material over the whole surface of a product cavity through the single shifting of a nozzle means regardless of the position and shape of the product cavity by a method wherein the discharge width of resin material of the nozzle means is controlled in accordance with the position or shape of the product cavity of the bottom half of a mold. CONSTITUTION:When an extruder reaches the predetermined position, the rotation of the screw of the extruder is started by the instruction from a controlling device 48 so as to extrude fluidized resin material 14 through a conduit 16 into the space of a nozzle 24. The extruded resin material 14 spreads in the space of the nozzle 24 in the longitudinal direction of the space and discharged from the opening with the discharge position and discharge width controlled by both blocks 34. The shifted positions of both the blocks 34, and the rotating speed of the screw of the extruder 10 and the shifting speed of the nozzle 24 are successively changed based upon the predetermined program so as to place the required amount of resin material 14 at the predetermined position of the product cavity.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method and apparatus for molding a resin material,
Specifically, the present invention relates to a method of placing a fluidized resin material in a product cavity of a lower mold of a mold consisting of an upper mold and a lower mold, and an apparatus for suitably carrying out the method.

(Prior art) A type of resin material molding device uses a mold consisting of an upper mold and a lower mold, and places a predetermined fluidized resin material along the product cavity of the lower mold, and then Some molds are designed to mold a predetermined molded product by placing an upper mold on top of a lower mold and clamping the mold.

By the way, in this type of molding equipment, conventionally,
As disclosed in Japanese Patent No. 17931, the nozzle means for discharging the fluidized resin material and placing it in the product cavity of the lower die is movable at least within a specific two-dimensional plane. The locus of the nozzle means is controlled according to a predetermined program depending on the position or shape of the product cavity. By discharging the resin material from the nozzle means that is moved along a predetermined trajectory, the required amount of the resin material is placed on each part of the entire surface of the product cavity.

(Problem to be solved by the invention) However, in such conventional molding equipment, the discharge width of the resin material is uniformly determined depending on the nozzle means used, so the product cavity has a relatively complicated shape. In contrast, it was necessary to use a nozzle means with a narrow discharge width for discharging the resin material in a rond or tube shape, and to move the nozzle means back and forth many times while sequentially shifting the nozzle means in the width direction of the product cavity. Therefore, in the past, it took a long time to place the resin material in the product cavity, which was one factor that prevented shortening of the molding cycle.

In addition, there is a problem that the molded product has a large number of welds, making it difficult to obtain sufficient mechanical strength, and there are also problems such as lack of thickness easily occurring and making it difficult to use materials with poor flowability. Furthermore, there is a problem in that charge marks (flow lines) of the resin material tend to remain clearly on the molded product, and such charge marks impair the aesthetic appearance of the molded product.

(Means for Solving the Problems) The present invention has been made against this background. That is, the gist of the method of the present invention is to use a mold consisting of an upper mold and a lower mold, place a predetermined amount of fluidized resin material along the product cavity of the lower mold, and then When molding a predetermined molded product by fitting the upper mold onto the lower mold and clamping the mold,
T capable of discharging the fluidized resin material in a predetermined width.
The nozzle means of the die structure is moved in one horizontal direction along the mold surface of the lower mold, and the resin material discharge width of the nozzle means is controlled according to the position or shape of the product cavity of the lower mold. , a predetermined amount of the fluidized resin material is placed on the lower mold along the product cavity.

Furthermore, in order to suitably carry out the above method, the apparatus of the present invention includes (a) an extruder for extruding the fluidized resin material; A nozzle means having a T-die structure having a longitudinal opening for discharging the material; , a regulating member that regulates the end of the opening; (dl) regulating member moving means that moves the regulating member in the longitudinal direction of the opening of the nozzle means;
) a nozzle moving means for moving the nozzle means in one horizontal direction orthogonal to the longitudinal direction of the opening; and (f) a movement position of the regulating member by the regulating member moving means and a movement of the nozzle means by the nozzle moving means. and a control device that controls the position according to a predetermined program, and according to the control by the control device, the resin material extruded from the extruder is placed on the lower mold of a mold consisting of an upper mold and a lower mold. , is configured to be discharged from the opening of the nozzle means and placed along the product cavity of the lower mold to perform a predetermined molding operation.

(Operation and Effects of the Invention) According to the method of the present invention, the resin material discharge width of the nozzle means is controlled according to the position or shape of the product cavity of the lower mold, so that regardless of the position or shape of the product cavity, By simply moving the nozzle means once along the mold surface of the lower mold, the resin material can be placed over the entire surface of the product cavity.

In other words, according to the method of the present invention, there is no need to shift the nozzle means in the width direction of the product cavity and reciprocate it many times in order to place the resin material over the entire surface of the product cavity, as in the conventional method. Therefore, the moving distance of the nozzle means can be shortened accordingly, the time for placing the resin material can be shortened, and the molding cycle can be shortened.

In addition, the occurrence of welds has been suppressed to a minimum, improving the mechanical strength of the molded product, making it difficult for under-walled areas to occur, making it difficult to use low-melt materials with poor flowability that were difficult to use in the past. Index materials have also become easier to use as molding materials. Furthermore, charge marks are less likely to occur, improving the aesthetic appearance of the molded product.

Further, in the method of the present invention, as described above, since the nozzle means only needs to be able to move in one horizontal direction, there is an advantage that the moving mechanism for the nozzle means can be made simple and inexpensive. That is, in the conventional method, in order to enable the nozzle means to move freely within at least a specific two-dimensional plane, it was necessary to provide moving means for moving the nozzle means in two orthogonal directions. However, in the method of the present invention, it is only necessary to move the nozzle means in one direction, and only one moving means is required, so that the moving mechanism can be configured easily and at low cost. . Furthermore, since the moving mechanism can be simplified, there is also the advantage that the installation space for the molding device can be reduced.

On the other hand, according to the device of the present invention, the method of the present invention can be suitably implemented and the above effects can be satisfactorily achieved.

(Example) Hereinafter, in order to clarify the present invention more specifically,
One embodiment thereof will be described in detail based on the drawings.

FIGS. 1 and 2 show an embodiment of the apparatus of the present invention. In those figures, 10 is an extruder that plasticizes and fluidizes a resin material 14 supplied from a hopper 12 and extrudes the fluidized resin material 14 into a conduit 16 by rotating a screw provided inside. and
Feed screw member 2 rotationally driven by electric motor 18
According to the rotation of 0, the feed screw member 2 moves on the base 22.
It can be moved in a horizontal direction parallel to the 0 axis direction. The conduit 16 is fixed to the extruder 10 parallel to the feed screw member 20, and a longitudinal nozzle 2 is provided at the tip of the conduit 16 in a T-shape with the conduit 16.
4 is fixed horizontally. Conduit 16 and nozzle 24
A nozzle means having a T-die structure is constructed from this. The resin material 14 extruded into the conduit 16 by the extruder 10 is discharged from the nozzle 24 and placed in the product cavity of the lower mold 26 of the mold. Note that, as is clear from the fact that the nozzle means is fixed to the extruder 10, in this embodiment, the extruder 10
An electric motor 18 and a feed screw member 20 for moving the
is used as a nozzle moving means.

The nozzle 24 extends from the bottom wall 28, in which the conduit 16 is opened, to the top wall 3, as shown in FIGS.
0 and the lower wall portion 32 have a U-shaped cross section extending parallel to each other in the horizontal direction (see FIG. 5). Then, in the space surrounded by the bottom wall 28, the top wall 30, and the bottom wall 32, with the opening of the conduit 16 sandwiched therebetween,
A pair of blocks 34 (only one is shown in the figure) are fitted, and these blocks 34 regulate the opening end of the nozzle 24 through which the resin material 14 is discharged. These blocks 34 are used as regulating members.

As shown in FIG. 6, the block 34 has guide protrusions 36 formed on its upper and lower surfaces, while the upper wall 30 and lower wall 32 of the nozzle 24
As shown in FIGS. 3 and 4, guide grooves 38 are formed in the longitudinal direction of the nozzle 24 (see FIG. 5). Further, as shown in FIGS. 3 and 4, a rack 40 is fixed to the block 34 so as to extend toward the end of the nozzle 24 (see FIG. 6). A pinion 43 fixed to the motor shaft of the electric motor 42 is meshed with a reduction gear 44 . When the electric motor 42 is rotated, the block 34 is moved in the longitudinal direction of the nozzle 24 while the guide protrusion 36 is guided by the guide groove 38 depending on the direction and amount of rotation. .

As is clear from this, in this embodiment, the rack 4
0. Electric motor 42. Pinion 43. fIi speed gear 44
The regulating member moving means is constituted by the above. This also applies to the block 34 provided at the opposite end. In addition, in FIGS. 3 and 4, 46 is
This is a closing member 46 that closes the longitudinal end of the space within the nozzle 24 .

In such a molding apparatus, as shown in FIG. 1, a control device 48 is provided, and the electric motors 18, 42.42° and The rotations of the motors that rotate the screws of the extruder 10 are controlled.

The operation of this embodiment will be explained below.

First, when a command to start a molding cycle is issued while the extruder 10 is in the retracted position shown by the two-dot chain line in FIG. The extruder 10 is moved forward in the right direction in the figure until the extruder 24 reaches the position shown by the dashed line. Then, when the extruder 10 reaches that position,
The screw of the extruder 10 is started to rotate in accordance with a command from the controller 48, thereby extruding the fluidized resin material 14 through the conduit 16 into the space of the nozzle 24. Then, the resin material 14 extruded into the space extends in the longitudinal direction within the space of the nozzle 24, as shown in (a), (b), (C), and (dl) of FIG. The opening of the conduit 16, which extends through the bottom wall 28 of the nozzle 24, is discharged from the opening with the discharge position and discharge width regulated by both blocks 34.
As shown in the figure, the taber 50 is opened toward the nozzle 24, thereby allowing the resin material 14 to spread smoothly in the longitudinal direction of the nozzle 24.

Also, at the same time as the screw starts rotating, the control device 48
The electric motor 18 is reversed in accordance with a command from the extruder 10, and the extruder 10 starts moving backward in the left direction in FIG. 2 at a speed according to a predetermined program. Furthermore, both blocks 3
The electric motors 42, 42 for moving the motors 4 are also started to be controlled according to respective predetermined programs. As a result, as shown in FIGS. 1 and 2, as the extruder 10 retreats, the resin material 1 is fluidized.
4 are placed in predetermined amounts on the lower die 26 along the product cavity. Then, when the nozzle 24 reaches a position corresponding to the rear end of the product cavity and the required amount of resin material is placed on the entire surface of the product cavity, the resin material 14 is cut off from the nozzle 24 by a cutter device (not shown). After that, the extruder 10 is retreated to the retracted position,
An upper mold (not shown) is fitted to the lower mold 26 and the molds are clamped.
A molded article of a predetermined shape is molded. Note that the rotational speed of the screw of the extruder 10 and the retraction speed of the extruder 10 by the electric motor 18 are determined in relation to each other and in consideration of the opening width (discharge width) of the nozzle 24 set by the block 34. This allows the required amount of resin material 14 to be placed approximately evenly over the entire surface of the product cavity.

As explained above, according to this embodiment, the extruder 10,
In other words, by moving the nozzle 24 once along the mold surface of the lower mold 26, the required amount of resin material 14 can be placed approximately evenly over the entire surface of the product cavity, and the amount of resin material 14 can be placed approximately evenly over the entire surface of the product cavity. This made it possible to significantly shorten the mounting time.

In addition, since the resin material 14 is simultaneously placed on the entire surface of the product cavity with one movement of the nozzle 24, the occurrence of welds is minimized and the mechanical strength of the molded product is significantly improved. Therefore, it becomes difficult for under-walled portions to occur, and it becomes easier to use a low melt index material with poor fluidity as the resin material 14. Furthermore, the appearance of the molded product is improved by avoiding the occurrence of charge marks, and the means for moving the nozzle 24 can be constructed easily and inexpensively.

Although one embodiment of the present invention has been described above, this is a literal illustration, and the present invention should not be interpreted as being limited to this specific example.

For example, in the above embodiment, the upper wall part 30 and the lower wall part 32 of the nozzle 24 were provided parallel to each other, but the upper wall part 30 and the lower wall part 32 are It may be provided so that the farther from 28, the closer it gets. In this way, the resin material 14 guided from the conduit 16 to the space inside the nozzle 24 will more easily flow in the longitudinal direction of the nozzle 24, and the amount of resin material 14 discharged from the opening of the nozzle 24 will be reduced. There is an advantage that the nozzle 24 is made more uniform in the longitudinal direction.

Further, in the embodiment described above, the opening of the nozzle 24 for discharging the resin material 14 was provided to open forward in the moving direction of the nozzle 24, but the opening is configured to open downward. It is also possible.

Further, in the embodiment described above, the conduit 16 and the nozzle 24 constituting the nozzle means were fixed relatively to the extruder 10, so that the nozzle 24 could be moved integrally with the extruder 10. Another bendable conduit is interposed between the conduit 16 and the extruder 10, and the extruder 10 is connected to the base 22.
Alternatively, the nozzle 24 may be fixed at the top and only the nozzle 24 may be moved.

Even in this way, the mechanism for moving the nozzle 24 can be made simpler and cheaper than the conventional one.

Further, in the embodiment, the block 34 as a regulating member
are provided at both ends of the nozzle 24, and both ends of the opening of the nozzle 24 can be changed arbitrarily according to a predetermined program, but one side in the width direction of the product cavity In such a case, the effect of the present invention can be achieved even if the block 34 is provided only at one end of the nozzle 24.

Further, in the above embodiment, the moving position of both blocks 34, the rotational speed of the screw of the extruder 10, and the moving speed of the nozzle 24 are sequentially changed according to a predetermined program, whereby the required amount is delivered to a predetermined part of the product cavity. However, by keeping either the rotational speed of the screw or the moving speed of the nozzle 24 at a constant speed and changing only the other speed sequentially, It is also possible to obtain similar effects.

Further, the extruder 10 does not necessarily have to be of a type that extrudes the resin material 14 using a screw, but may be of a type that extrudes it using a cylinder. This means that the moving means for moving the nozzle 24 and the block 3
The same can be said about the moving means for moving 4. Further, the extruder 10 does not necessarily have to have the function of fluidizing the resin material 14, and may have only the function of simply extruding the resin material 14 that has been fluidized in advance.

Although not listed here, it goes without saying that the present invention can be implemented with various modifications, variations, and improvements within the scope of the invention.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an example of a device for suitably implementing the present invention, and FIG. 2 is a plan view of FIG. 1 excluding the control system.
It is an arrow view. FIG. 3 is an enlarged plan sectional view showing the main parts of the nozzle in the device shown in FIG. 1, and FIG.
It is a V-IV sectional view. 5 is a sectional view taken along the line V-V in FIG. 4, and FIG. 6 is a perspective view showing the block and rack in FIG. 3. (a), (b), (C), and (d+ in FIG. 7) are explanatory views showing how the discharge position and discharge width of the resin material discharged from the nozzle change in the apparatus of FIG. 1, respectively. .

Claims (2)

[Claims] (1) Using a mold consisting of an upper mold and a lower mold, place a predetermined amount of fluidized resin material along the product cavity of the lower mold, and then place the upper mold on the lower mold. In addition, by clamping the mold, the fluidized resin material can be discharged in a predetermined width when molding a predetermined molded product.
The nozzle means of the die structure is moved in one horizontal direction along the mold surface of the lower mold, and the resin material discharge width of the nozzle means is controlled according to the position or shape of the product cavity of the lower mold. . A method for molding a resin material, characterized in that a predetermined amount of the fluidized resin material is placed on the lower mold along the product cavity. (2) an extruder for extruding a fluidized resin material; a nozzle means having a T-die structure connected to the extruder and having a longitudinal opening for discharging the resin material extruded from the extruder; a regulating member disposed movably in the longitudinal direction of the opening on at least one longitudinal end of the opening of the nozzle means to regulate the end of the opening; A regulating member moving means for moving in the longitudinal direction of the opening; a nozzle moving means for moving the nozzle means in one horizontal direction perpendicular to the longitudinal direction of the opening; and a movement position of the regulating member by the regulating member moving means. and a control device that controls the movement position of the nozzle means by the nozzle moving means according to a predetermined program, and according to the control by the control device, the resin material extruded from the extruder is moved between the upper mold and the lower mold. A resin material characterized in that the resin material is discharged from the opening of the nozzle means and placed on the lower mold of a mold consisting of a mold along the product cavity of the lower mold to perform a predetermined molding operation. molding equipment.